Abstract
A pregnane steroid, 3α-hydroxy-pregn-7-ene-6,20-dione (1), was isolated from a Hydractiniaassociated
Cladosporium sphaerospermum sp. SW67 by repetitive column chromatographic separation and highperformance
liquid chromatography (HPLC) purification. The planar structure of 1 was elucidated from the
analysis of the spectroscopic data (1D and 2D NMR spectra) and LC-MS data. The absolute configuration of 1
was determined by interpretation of ROESY spectrum of 1, together with the comparison of reported
spectroscopic values in previous studies. To the best of our knowledge, this is the first report of the identification
of the pregnane scaffold from C. sphaerospermum, a natural source. Compound 1 was evaluated for its effects on
lipid metabolism and adipogenesis during adipocyte maturation and showed that compound 1 substantially
inhibited lipid accumulation compared to the control. Consistently, the expression of the adipocyte marker gene
(Adipsin) was reduced upon incubation with 1. Further, we evaluated the effects of 1 on lipid metabolism by
measuring the transcription of lipolytic and lipogenic genes. The expression of the lipolytic gene ATGL was
significantly elevated upon exposure to 1 during adipogenesis, whereas the expression of lipogenic genes FASN
and SREBP1 was significantly reduced upon treatment with 1. Thus, our findings provide experimental evidence
that the steroid derived from Hydractinia-associated C. sphaerospermum sp. SW67 is a potential therapeutic agent
for obesity.
Leibniz-HKI-Authors
Identifier
doi: 10.20307/nps.2020.26.3.230